Art of scaling metal objects



april 7, 1925.

w. J. voLLARATH ART oF scALING METAL gjBJ'EcTs Filed Dec. 8. 1923 Patented Apr. 7, 1925.

UNITED sTA'i iz s` 1,532,189 PATENT oFFicE.

WALTER J. VOLLBATH, SHEBOYGAN, WISCONSIN, ASSIGNOR TO POLAR WARE COMPANY, OF SHEBOYGAN, WISCONSIN, A. CORPORATION OF WISCONSIN.

ART OF SCALING METAL OBJECTS.

Applicationvled December 8, 1923. Serial No. 679,400.

To all whom it may concern:

Be it known that I, WALTER J. VOLI.- RATH, a citizen of the United States, residing at Sheboygan, in the county of Sheboygan and State of Wisconsin, have invented a new and useful Improvement in the Art of Scaling Metal Objects, of whiclithe following is a specification.

My invention relates generally to the scaling of metal objects, more particularly for rendering'their surfaces smooth and clean, as, for example, in the manufacture of porcelain-coated metal objects in which manufacture it is desired that the surfaces of the objects be rendered smooth and clean before the so-called pickling operation which precedes the operation of coating the objects with porcelain.

In the production of porcelain-coated metal objects,it is customary to anneal the metal objects beforeA pickling them, and under such conditionsy the scaling process may be effected concurrent with the annealing operation, the heat for annealing also performing in connection with the scaling operation.

My primary object is to provide a novel and simple method of scaling and one by which the objections commonly incident to the present methods of scaling are avoided, whereby uniform scaling" of the group lof objects located in a furnace may be effected and direct contact of the Workmen with the chemicals used avoided. Another object is to provide a novel and simple construction by which the advantages above stated may be effected.

' Referring to the accompanying drawing:

Figure 1 is a view in front elevation. of apparatus suitable for carrying out my irnproved method; and Figure`2, a view in vertical sectional elevation taken through a side of the furnace and showing a portion of the device by which the acid used in carrying out the process is sprayed into the furnace chamber.

Generally stated, my improved' method consists in spraying into a chamber in which the metal articles to be treated and in heated condition are located, any suitable acid, as, for example, muriatic or sulphuric acid, which in contacting with the metal, and under the action of heat, causes the objects to become scaled by virtue of the loosening of the scale which may have been previously formed thereon and the forming of addiintroduced into, and withdrawn from, thel furance chamber. The acid spray is introduced into the furnace chamber at any desirable point in any of its walls. In the particular construction shown provision is made for introducing the acid spray through a side wall of the chamber, this wall, to this end, containing an opening 5 which coinmunicates at its inner end with the furL nace chamber. Located outside of the furnace 3 and adjacent to the outer end of the opening 5 are means for spraying the acid through the hole 5 and into the furnace. These means may be of any desirable construction, those shown comprising 'a tank 6 for receiving the acid and into which the lower open end of a pipe 7 extends, the upper end of this pipe having the nozzle 8 which is located closely adjacent to the outer extremity of the nozzle 9 of an airpipe 10 supplied with air under pressure from any suitable source (not shown), the

nozzle 8 being located in tle path of the air issuing from the nozzle 9 whereby the air discharged from the nozzle 9 and through the opening 5 into the furnace chamber becomes charged with acid drawn fromthe tank 6 through thepipe 7 under the injector action produced by the air. The acid spray introduced into the furnace chamber substantiallyA uniformly contacts with the exposed. surfaces of the metal objects to be treated and located in the furnace chamber and, under the action of the heat in the chamber 3, causes loose scale to become formed on the metal objects, resulting in the production of clean and smooth surfaces.

The furnace shown, in accordance with common practice, is provided with any suitable means for heating the objects in its chamber, and where my improved method is to be used in connection with the simultaneous annealing of the objects, the heat ,for annealing would also furnish the desired heatfor coo ration with the acid, in effecting the ro uction of the loose scale. It will be un erstood, however, that my improved scaling method may also be used where it is' not desired to simultaneously amical-the objects, in which case the surface of the objects to be scaled Should be heated to the desired temperature preferably substantially to annealing tem rature.

It will be understood 'from -the oregoing that by employing my improved method and apparatus I am not only able to effect a substantially uniform scaling operation as to all of the objects located in the furnace chamber but render unnecessary direct contact of the workmen with the acid and the splashing or dripping of the acid upon the ground surrounding the furnace, with the manifest advantage.

. comprisin While I have described certain apparatus for practicing mv improved method, and illustrated structural features of my invention, I do not wish to be understood as limiting the invention thereto as the method may be practiced with other apparatus and various changes and modifications made in the apparatus shown without departing from the spirit of my invention.

What I claim as new, and desire to secure by Letters Patent, is:

1. The method of scaling metal objects which consists in subjecting them, while confined in a chamber and while in heated condition, to an acid-spray.

2. The method of scaling metal objects which consists in subjecting them, while confined in a chamber, to heat and an acidspray simultaneously.

3. Apparatus for the purpose set forth,

a heating chamber for'the articles, an means for spraying acid into said chamber, for the purpose set forth.

WALTER J. VOLLRATH. 

